The sting — called "Operation Money Tree" — started after a grandmother called authorities when she learned that the father of her granddaughter traded his electronic food stamp card for money instead of buying groceries for her granddaughter, authorities said.

The cards were allegedly traded at a small grocery store in Palm Springs, authorities told WPTV.

The clerks at the store, however, would give the suspects cash and keep half the profits for themselves.

For instance, if a suspect sought $100, the clerk would charge $150 to the card — handing the cash over the suspect, authorities said.

In March, Florida welfare officials announced a crackdown on fraud in the state, which cost taxpayers $1.35 billion last year, the Orlando Sentinel reports.

The effort partnered the Florida Department of Children and Families with LexisNexis to use an identity-authentication process similar to what banks and other financial institutions employ.

The agency processes most of the applications for those seeking food stamps, cash to needy families, and Medicaid benefits.

The technology by the data-services company requires welfare recipients to answer personal questions that identity thieves would not be able to answer, the Sentinel reports.

The change was expected to save $60 million a year, the report says. About 90 percent of the state's welfare recipients complete their benefit applications online.

"Florida ranks No. 1 in the nation for identity theft, and for far too long criminals have been gaming our systems and stealing from taxpayers and Floridians who are truly in need," DCF Secretary David Wilkins told the Sentinel when the program was announced in March.

"Implementing technology that has been successfully used in the private sector will allow us to catch more of these cheats on the front end."